The Senescence of Spermatozoa

Abstract

1. A freshly prepared dilute suspension of the spermatozoa of Echinus has a respiratory level higher than that of an actively beating vertebrate heart, since 1 gm. of cells may consume (at 17° C.) about 8 c.c. of oxygen during the first hour of its active life. The respiratory level soon falls, so that the total oxygen consumed during life is not more than about 32 c.c. of oxygen per gm. of cells. 2. The decline in the activity of a suspension of spermatozoa can only be regarded as due to a process of spontaneous irreversible decay (or to an exhaustion of food reserves) if it be assumed that the suspension is essentially a heterogeneous population whose units are distributed according to a probability curve of a particular type. From this point of view, senescence is irreversible. 3. At the same time the decline in activity of a suspension can also be harmonised with the hypothesis that senescence is due to a process of auto-intoxication whereby the products of activity inhibit the essential reactions of life. From this point of view senescence is reversible.